1. Field
The present disclosure relates to nitrogen-doped carbon quantum dots and a method for producing the same. More particularly, the present disclosure relates to nitrogen-doped carbon quantum dots obtained by using a single process and a method for producing the same.
2. Description of the Related Art
Since a carbon-based material having a soccer ball-like structure, called fullerene, was discovered in 1985, various structures having excellent physical, chemical and electrical properties have been produced and discovered, such structures including graphene, carbon nanotubes, carbon nanocones, carbon nanoonions, carbon nanorings and carbon quantum dots having the smallest size of several nanometers. Carbon quantum dots do not have a complete carbon crystal shape but are nanometer-scaled carbon structures having unique physical and optical properties. Such carbon quantum dots are shown to have high applicability in various industrial fields, and thus they have been studied intensively. Particularly, carbon quantum dots with a nanometer-scaled size have semiconductive properties, and thus show fluorescence properties varied with particle sizes and functional groups at the edges thereof. In addition, carbon quantum dots show different fluorescence properties at different wavelengths of excitation light. Further, since carbon quantum dots have no transition metal, they are eco-friendly materials and are expected to be studied about their applications in the future.
However, although carbon quantum dots have high applicability in various industrial fields, their preparation according to the related art includes a complicated process due to purification and separation, requires a lot of time, and provides low yield. Thus, studies about application of carbon quantum dots are limited. In addition, there is a difficulty in separating acid used for forming carbon quantum dots having a very small size. Moreover, a high-temperature process or harmful material is used during the reduction of oxidized carbon nanomaterials. Therefore, there is a need for preparing eco-friendly carbon quantum dots to solve the above-mentioned problems.